Asphalt compositions



UnitedStat at i.

"fhis' invention pertains to improvements in asphalt tutoring ositiotis andtmore particularly relates to asphalt compositions having improved hardening resistant prep- .IRes istancetomindue hardening is *an impbrtantproperty -r'e'quirement lof asphalts, particularly penetration grade rpaving asph'alts and. in man =localities1-asphalts for paving :end: .other. 1 purposes \must possess wcet tai-n specifications which indicate resistance to un'd'ue hardening, which propertyais measured in terms vof reeover'y penetration. eIn br ief, :this' test. measures the penetration of asphalts recovered from finished asphalt pavements orrecovered inom asphalts' whichhave been subjectedto certain specirfied-rcoriditiorisrwhich normally promote the hardenin of casphalticpmaterials. Since normally the recovery. of i an asphalt material from a finished :pavemenfl-ma'y *be inconvenient, and does not evaluate the properties of the asphalt prior to 'pavin'g, alsberamry procedure has been devised for measuringthe resistance to hardening in terms Wot recovery penetration.

The "'test kfnowrra's the Detroit recovery testf'consistsiof jecitingtlre asp'halt to the so=calledShattuckyoxidation "t' desci ibed in Association or Paving Technologists Proceedings, Technical Sessions; vol. it 1940),j p. 18 6- andsubsequently'submittingtlreproduct'frotn the *Shattucic oxidation test 'to the Abson recovery method, described in A. S. T. M. Proceedings, 1933 (vol. 33), pp. 704-711. In the Shattuck oxidation procedure, 1880 grams standard Ottowa silica sand, heated to 400 F. and 120 grams of asphalt heated to 300 F. are introduced into a pug mixer, heated to an inside temperature of 275 F. to 300 F. and mixed for one minute at 75 R. P. M. The mixture is then removed from the mixer and spread evenly in a straight side shallow metal pan having the dimensions of 7 inches x 11 inches x 1% inches deep. The pan is immediately placed in a thermostatically controllcd'electric oven, heated at 350 F. for exactly thirty minutes. The mixture is then removed from the oven, cooled and the asphalt recovered by the Abson method.

The Abson method involves extraction of the asphalt with benzol in a Soxhlet-type extractor, and the solvent removed by distillation in an atmosphere of carbon dioxide. The penetration of the solvent-free recovered asphalt is then determined by A. S. T. M. Method 45-49.

In many localities the specifications for paving asphalts require that the penetration of the asphalt recovered from finished pavements must be at least 50% of the original penetration for resurfacing Work and at least 60% of the original penetration for new road work. Asphalts obtained from asphaltic crude oils usually meet the specified recovery penetration. However, asphalts obtained from mixed crude oils containing waxes, such as paraflin Waxes, frequently have a recovery penetration of less than 50% and are unsatisfactory with respect to resistance to hardening.

It is an object of the present invention to provide a wax-containing asphalt which will have a recovery penetration of at least 50%. Another object of the invention is to provide a wax-containingpenetration grade paving asphalt which is resistant to hardening. -A furtherobje'ct :of invention is toprovide a method of increasingfthe' esist-ance to hardening of wax-containing paving adpht'alts. .St-ilhanot-her objectef the inventionis toprovide a method -.of increasing therecovery penetration of wax-containing .pavingasphalts to a value of at -l'east 50% of the-original penetration of such asphalt Other objects and advantages will become apparent rfrom the followingdescription thereof. x I m.

, In accordance with the present invention the resistance to hardening characteristics of wax-containing asphnlts, particularly. penetration grade paving aspihalts, isenhancetl by incorporating in such asphalts from about 0.1% to about l0% -and preferably' from 0.5% to-5% of eteondens ation product of an aromatic compound and a densible aliphatic compound having more than IOparbon atoms. These, condensation .products are preferably made by Friedel-Grafts condensation 'of :an aromatic comppund with a relatively long chain aliphatic cornpoundcontaining areactivegroup, such as a-replaeeabl'e halogen atom, preferably chlorine atom, or;an olefilric linkage, sue-b as for example, chlorinated paraflin wax, chlorinated heavy parafiin oil, chlorinated montan wax, or means derived theretrernisy the removal or he rye-regen chloride without cracking the CC linkage. The aromatic compound may be an aromatic hydrocarbon, or various derivatives thereof, such as aromatic hydrocarbons containing low molecular weight alkyl groups, such as methyl, 'ethyl, etc., or otherconst-ituents, such-as 'hydroxy or alkoxy groups, such as for example, sesame. naphthalene, toluene, xylene, aiphenyi, phenol, etc. "Sev- ,er'a1 mat'erials suitable for use in the present "inven'tipn for the ipu'rpps of improving the resistance to hardening er 'sb11'cl "sph2iltic materials are available One such ems 5511 d is a pro uct tmbwn as Pdfirex, when r a n th' lens-eliminates parents cdndehs Annex; 1. .1.

psretijgbv the methods descr bed 'in "U. 963 917, "1,9"63918 and 2,057, uct marketed under, the trade name, P fl' by condensing anemic tfo "roars y Wei t er nap u lene witir''o thaw-arts byweightbitfihlorihated'paraifih wax containing about 10 to 15% chlorine in the presence of a Friedel-Crafts catalyst, such as aluminum chloride. Another product marketed by Monsanto Chemical Company under the trade-name Stanopour is made by similar condensation of phenol with chlorinated parafiin wax in the presence of aluminum chloride, which product may or may not be further reacted upon with a resinifying agent, such as acyl halides, for example, phthalyl chloride. These condensation products are oil-soluble having molecular weights above 500 and may range as high as 2000 or 5000, or more.

As an example of one method of making the wax condensation products employed in our process, paraffin wax having a melting point of 126 F.-l30 F. may be heated with chlorine in a glass lined vessel until the amount of chlorine absorbed by the wax reaches 10% to 15%. The resulting chlorinated wax may then be mixed with about 10% of its weight of napthalene and to the melted mixture at a temperature of F. to 400 F. there is added, with vigorous agitation, 5% to 10% of anhydrous aluminum chloride. The reaction proceeds rapidly and within 30 minutes the reaction is substantially complete. The reaction mixture is then washed with water and neutralized, a hydrocarbon diluent being added at this stage to facilitate handling the heavy condensation prod.- ucts. A suitable diluent may be naphtha, kerosene or other light hydrocarbon oil. After neutralization it is preferred to remove the diluent by distillation.

The condensation product may be incorporated in the solid asphaltic material by well known and convenient methods, such as by stirring while the asphaltic material isheated and in a fluid state. Other additives for bituminous materials, such as wet mineral aggregate coating agents, may be incorporated in the asphalt materials containing the condensation products herein described. The present invention is applicable to'increasing the resistance to hardening of wax-containing normally liquid asphalts such as road oils, cutbacks, wood treating asphalts, etc., or normally semi-solid or solid asphalts ob- -tained by vacuum and/or steam reduction, including penetration grade paving asphalts, or oxidized waxcontaining'asphalts, such asroofing asphalts, paper'coating asphalts, canal lining asphalts, etc.

Penetration grade wax-containing asphalts or waxcontaining asphalt cements are fluxed or unfluxed as- -phal'ts'having a penetration at 77 F. of between about and 300 under a load of 100 grams applied for five seconds. The following example illustrates a specific embodiment of the herein described invention. A solid paving asphalt preparedby steam and vacuum reduction of a wax-containing Texas crude oil and a blend of this asphalt containing 0.5% of 'Pourex, a condensation product obtained by the aluminum chloride condensation of-naphthalene with paraffin wax containing %-15% chlorine were subjected to the above described recovery test procedure and the following results obtained:

Recovery penetration of wax containing paving asphalt Original Penetra- Recovery Asphalt Penetratlon After Pen.,

tion Test Percent (A) Wax-containing West Texas'As- .phalt'. 111 41 37 (B) 'A+0.5 Pourex" 94 57 61 It isn'ot intended that this invention be limited to the particular example, which has been given merely for illustration, but only by the appended claims in which it is intended to claim all novelty inherent in the invention as well as other modifications coming within the scope and spirit of the invention.

We claim:

1. A paving asphalt composition having improved resistance towards hardening, comprising a major proportion of a wax-containing paving asphalt normally susceptible to hardening, and from 0.1% to about 10% of an aluminum chloride condensation product of an aromatic hydrocarbon and a chlorinated parafiin wax.

2. A paving asphalt composition having a recovery penetration of at least about comprising a major proportion of a wax-containing paving asphalt normally having a recovery penetration of less than about 50%, and from 0.1% to about 10% of an oil-soluble aluminum chloride condensation product of naphthalene and a ch1o rinated parafiin wax containing from about 10% to about 15% chlorine, I I v 3. An asphalt cement composition having improved resistance to hardening comprising a major proportion of a wax-containing asphalt cement normally susceptible to hardening and from about 0.1%to about10% of an aluminum chloride condensation product of an aromati hydrocarbon and a chlorinated paraflin wax.

4. An asphalt composition comprising a major proportion of a wax-containing asphalt and from 0.1% to about 10% of a condensation product of an aromatic compound selected from the class consisting of an aromatic hydrocarbon and a phenol and a chlorinated paraflin wax, said condensation being carried out in the presence of a Friedel-Crafts catalyst. f

References Cited in the file of this patent UNITED STATES PATENTS 2,085,373 Loane June 29, 1937 2,191,295 Dohse- .Feb. 20, 1940 2,248,749 Engelhardt July 8, 1941 2,429,565 Reilf Oct. 21, 1947 2,465,960 Berge Mar. 29, 1949 2,492,848 Crouch et al. Dec. 27, 1949 

4. AN ASPHALT COMPOSITION COMPRISING A MAJOR PROPORTION OF A WAX-CONTAINING ASPHALT AND FROM 0.1% TO ABOUT 10% OF A CONDENSATION PRODUCT OF AN AROMATIC COMPOUND SELECTED FROM THE CLASS CONSISTING OF AN AROMATIC HYDROCARBON AND A PHENOL AND A CHLORINATED PARAFFIN WAX, SAID CONDENSATION BEING CARRIED OUT IN THE PRESENCE OF A FRIEDEL-CRAFTS CATALYST. 